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-rw-r--r--crypto/ecc.c44
1 files changed, 39 insertions, 5 deletions
diff --git a/crypto/ecc.c b/crypto/ecc.c
index 02d35be7702b..8acf8433ca29 100644
--- a/crypto/ecc.c
+++ b/crypto/ecc.c
@@ -940,7 +940,7 @@ static bool ecc_point_is_zero(const struct ecc_point *point)
}
/* Point multiplication algorithm using Montgomery's ladder with co-Z
- * coordinates. From http://eprint.iacr.org/2011/338.pdf
+ * coordinates. From https://eprint.iacr.org/2011/338.pdf
*/
/* Double in place */
@@ -1404,7 +1404,9 @@ int ecc_make_pub_key(unsigned int curve_id, unsigned int ndigits,
}
ecc_point_mult(pk, &curve->g, priv, NULL, curve, ndigits);
- if (ecc_point_is_zero(pk)) {
+
+ /* SP800-56A rev 3 5.6.2.1.3 key check */
+ if (ecc_is_pubkey_valid_full(curve, pk)) {
ret = -EAGAIN;
goto err_free_point;
}
@@ -1452,6 +1454,33 @@ int ecc_is_pubkey_valid_partial(const struct ecc_curve *curve,
}
EXPORT_SYMBOL(ecc_is_pubkey_valid_partial);
+/* SP800-56A section 5.6.2.3.3 full verification */
+int ecc_is_pubkey_valid_full(const struct ecc_curve *curve,
+ struct ecc_point *pk)
+{
+ struct ecc_point *nQ;
+
+ /* Checks 1 through 3 */
+ int ret = ecc_is_pubkey_valid_partial(curve, pk);
+
+ if (ret)
+ return ret;
+
+ /* Check 4: Verify that nQ is the zero point. */
+ nQ = ecc_alloc_point(pk->ndigits);
+ if (!nQ)
+ return -ENOMEM;
+
+ ecc_point_mult(nQ, pk, curve->n, NULL, curve, pk->ndigits);
+ if (!ecc_point_is_zero(nQ))
+ ret = -EINVAL;
+
+ ecc_free_point(nQ);
+
+ return ret;
+}
+EXPORT_SYMBOL(ecc_is_pubkey_valid_full);
+
int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits,
const u64 *private_key, const u64 *public_key,
u64 *secret)
@@ -1495,11 +1524,16 @@ int crypto_ecdh_shared_secret(unsigned int curve_id, unsigned int ndigits,
ecc_point_mult(product, pk, priv, rand_z, curve, ndigits);
- ecc_swap_digits(product->x, secret, ndigits);
-
- if (ecc_point_is_zero(product))
+ if (ecc_point_is_zero(product)) {
ret = -EFAULT;
+ goto err_validity;
+ }
+
+ ecc_swap_digits(product->x, secret, ndigits);
+err_validity:
+ memzero_explicit(priv, sizeof(priv));
+ memzero_explicit(rand_z, sizeof(rand_z));
ecc_free_point(product);
err_alloc_product:
ecc_free_point(pk);